To investigate whether the collapsibility index of the inferior vena cava
recorded during a deep standardized inspiration predicts fluid responsiveness
in nonintubated patients.
Prospective, nonrandomized study.
ICUs at a general and a university hospital.
Nonintubated patients without mechanical ventilation (n
= 90) presenting with sepsis
-induced acute circulatory failure and considered for volume expansion.
We assessed hemodynamic
status at baseline and after a volume expansion induced by a 30-minute infusion of 500-mL gelatin 4%.
Measurements and Main Results:
We measured stroke volume index and collapsibility index of the inferior vena cava
under a deep standardized inspiration using transthoracic echocardiography
. Vena cava pertinent diameters were measured 15–20 mm caudal to the hepatic vein junction and recorded by bidimensional imaging on a subcostal long-axis view. Standardized respiratory cycles consisted of a deep standardized inspiration followed by passive exhalation. The collapsibility index expressed in percentage equaled the ratio of the difference between end-expiratory and minimum-inspiratory diameter over the end-expiratory diameter. After volume expansion, a relevant (≥ 10%) stroke volume index increase was recorded in 56% patients. In receiver operating characteristic analysis, the area under curve for that collapsibility index was 0.89 (95% CI, 0.82–0.97). When such index is superior or equal to 48%, fluid responsiveness
is predicted with a sensitivity of 84% and a specificity of 90%.
The collapsibility index of the inferior vena cava
during a deep standardized inspiration is a simple, noninvasive bedside predictor of fluid responsiveness
in nonintubated patients with sepsis
-related acute circulatory failure.